Category Archives: Ubuntu

Post that are about the GNU Linux distribution from Ubuntu

Using chrony on Ubuntu 18.04

Using chrony on Ubuntu 18.04 will show how to setup chrony for clients and servers within your LAN. Chrony replaces NTP which in now depreciated. Using chrony on Ubuntu 18.04 will show how to setup chrony for clients and servers within your LAN.

Chrony is an implementation of the Network Time Protocol (NTP). It is used to keep the system clocks of PCs synchronized with the clock of NTP servers. It can also be used to setup your own NTP server to provide time for your LAN. Chrony replaces ntp and ntpdate which are now deprecated.

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Mail Server On Ubuntu 18.04 Part 4

Welcome to Mail Server on Ubuntu 18.04 Part 4. This is the forth part of a series of blog posts. We will be adding some extra checking to postfix. This will allow you to effectively blacklist some domains and email addresses. We will also be adding checks for properly formatted domain names and checking the IP address against their DNS lookup.

Mail Server on Ubuntu 18.04 Part 1
Mail Server on Ubuntu 18.04 Part 2
Mail Server on Ubuntu 18.04 Part 3

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Mail Server on Ubuntu 18.04 Part 3

Welcome to Mail Server on Ubuntu 18.04 Part 3. This is the third part of a series of blog posts. In this post we will be adding anti-virus and anti-spam along with some other tools to stop spam and viruses getting through to our mailserver.

Mail Server on Ubuntu 18.04 Part 1
Mail Server on Ubuntu 18.04 Part 2

  • Emails will be checked with anti-virus service ClamAV
  • Emails will be checked with anti-spam filters from Spamassassin
  • Grey listing of incoming mail servers with Postgrey

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Mail Server on Ubuntu 18.04 Part 2

Welcome to Mail Server on Ubuntu 18.04 Part 2. This is the second part of a series of blog posts. The mailserver will use Postfix, Dovecot and Amavis. To see Mail Server on Ubuntu 18.04 Part1 follow the link.

In Mail Server on Ubuntu 18.04 Part 2 we will turn on the ability for any user to send and receive emails once they are known to the system via a MySQL database. This is called using virtual users. We will also turn on the ability to use encrypted connections with TLS.

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Start Stop VirtualBox with systemd

This post will show how to start stop Virtualbox with systemd. The documentation for both auto-starting virtualbox and that for systemd I found to be appalling. The virtual box documentation has an example but that is wrong. The example code is bash and it is sourced by another file. There is a variable assignment at the top but it has spaces around the equals so it fails with a schoolboy syntax error. For systemd what there is, and there is a lot of it, does not make sense. The man pages have lots of English words that go together to mean nothing but the usual marketing bullshit we are constantly get bombarded with.

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DNSCrypt and dnsmasq on Ubuntu 18.04

This is how I got DNSCrypt and dnsmasq on Ubuntu 18.04 working together. dnsmasq is used for local domains and DHCP while we use DNSCrypt as our forwarding DNSD server. To quote from the OpenDNS website “DNSCrypt is a piece of lightweight software that everyone should use to boost online privacy and security. It works by encrypting all DNS traffic between the user and OpenDNS, preventing any spying, spoofing or man-in-the-middle attacks.”.

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Test Networking Lab Ubuntu On 18.04

Test Networking Lab Ubuntu on 18.04

Overview

I wanted to create a test networking lab Ubuntu on 18.04 to try out configurations without having to hack my real LAN about. I decided to use VirtualBox virtual machines as the software is freely available and works with Linux very nicely. For the network in the test networking lab Ubuntu on 18.04 we will need to separate from our own normal LAN. VirtualBox provides this in of the box. We simply set the network interfaces to use “Internal Network”. This way any gust VMs on the host within the internal network can only see each other.

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Mail Server on Ubuntu 18.04 Part 1

Welcome to Mail Server on Ubuntu 18.04 Part 1. This is the first part of a series of blog posts. It will use Postfix, dovecot and amavis. Setting up a mail server is a complex project it is one of the most difficult and complex servers to setup. There are many different tools/packages that have to come together before it is working. There are many more packages that can be installed before you have something that is usable in the real world with all the hackers and spammers around.

*Do not follow this blog post on a production server unless you are
 [crazy|dumb|mad|nutz|stupid] and want to be unemployed!

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